Holding device

Abstract

To provide a new holding means capable of exhibiting high attraction force in an on-state without depending on an electromagnet, having good sharpness of magnetic force in an off-state, facilitating removal of a held object, being made smaller and thinner than a conventional article, and being applied to various scenes including a scene to which the conventional article is difficult to be applied.SOLUTION: The holding device of the present invention has a configuration in which a movable plate on which a permanent magnet is mounted is disposed between upper and lower plates, a non-magnetic region is provided between a holding portion formed of a magnetic member and a magnetic flux completion portion in a front view of the device, and an on state in which the permanent magnet is connected only to the holding portion and an off state in which the permanent magnet is connected only to the magnetic flux completion portion are switched by leftward and rightward movement of the movable plate. According to such a configuration, it is possible to reduce the size and thickness of the permanent magnet holding device as compared with the conventional permanent magnet holding device while maintaining the attractive holding force at the time of ON and the sharpness at the time of OFF.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a holding device that holds an object by magnetic force. [Background technology]

[0002] Various devices that use magnetic force to hold or grip objects have been known for some time. For example, in the field of machining, magnetic chucks are used to secure workpieces by magnetic attraction. Magnetic chucks are classified into permanent magnet type, electromagnet type, and electropermanent magnet type, which combines the two. Permanent magnet type chucks are primarily used in grinding and electrical discharge machining, which require less force in the lateral direction. On the other hand, electromagnet type chucks can achieve strong attraction, making them resistant to lateral forces. They are also easy to use because they can electrically switch between attraction and release states, making them suitable for cutting, which requires large forces in the lateral direction. However, electromagnet type chucks naturally require a power source and a cooling mechanism to suppress heat generation due to large currents. This requires careful attention to electrical insulation and waterproofing, resulting in high installation and running costs. Since they require a continuous high current to attract the workpiece, they also have a significant environmental impact.

[0003] Magnetic chucks for machining typically have a structure in which magnetic and non-magnetic materials are alternately arranged in stripes (see Patent Documents 1 and 2). In conventional magnetic chucks, the periodicity of the magnetic and non-magnetic stripes is fine, and is unrelated to the size of the internal magnet. While magnetic chuck technology was already established in the 1980s, the development of magnetic chuck products, particularly permanent magnet magnetic chucks, has progressed toward an ever-finer pattern of magnetic and non-magnetic materials. Meanwhile, Patent Document 3 describes a holding device that, by matching the periodicity of the stripes with the size and spacing of the internal magnets in a conventional magnetic chuck, achieves both strong holding force and good cutting performance when released, even in permanent magnet magnetic chucks. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 52-167668 [Patent Document 2] Japanese Utility Model Application Publication No. 57-48033 [Patent Document 3] Patent No. 5716232 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional permanent magnet holding devices had to be constructed to a certain size or larger in order to maintain sufficient attractive force and sharpness when turned off, which limited their miniaturization.The present invention aims to provide a new holding means that can exert high attractive force when turned on without relying on an electromagnet, and has sharp magnetic force when turned off, making it easy to remove the held object, and that can be made smaller and thinner than conventional products, and can be used in a variety of situations, including those where conventional products have been difficult to use. [Means for solving the problem]

[0006] As a result of extensive research, the inventors of the present application have discovered that by arranging a movable plate equipped with a permanent magnet between upper and lower plates, and providing a non-magnetic area between the holding section formed of a magnetic material and the magnetic flux completion section when viewed from the front of the device, and by moving the movable plate left and right to switch between an ON state in which the permanent magnet connects only to the holding section and an OFF state in which it connects only to the magnetic flux completion section, it is possible to make the device smaller and thinner than conventional permanent magnet type holding devices while maintaining the attractive holding force when on and the sharpness when off, and have completed the present invention, which includes the following aspects.

[0007] [1] A holding device that holds an object, at least a part of which is made of a magnetic material, by magnetic force, an upper plate including an upper right magnetic member, an upper left magnetic member, and an upper non-magnetic member disposed therebetween; a lower plate including a right lower magnetic member, a left lower magnetic member, and a lower non-magnetic member disposed therebetween; A movable plate in which a magnetic pole band, which is made of at least one permanent magnet and has a magnetic pole surface facing up and down, is arranged on a non-magnetic plate body; Equipped with the movable plate is disposed between the upper plate and the lower plate and is movable in the left-right direction; the upper right magnetic member and the lower right magnetic member are spaced apart and do not contact each other, and these magnetic members form the holding portion of the holding device; the upper left magnetic member and the lower left magnetic member are spaced apart and do not contact each other, and these magnetic members form a magnetic flux completion portion of the holding device; the upper non-magnetic member and the lower non-magnetic member are arranged side by side in the vertical direction to form a non-magnetic region between the holding portion and the magnetic flux completing portion; A holding device in which the movable plate can be moved left and right to switch between an ON state in which the magnetic pole band is connected only to the holding portion on the right side of the non-magnetic area, and an OFF state in which the magnetic pole band is connected only to the magnetic flux completion portion on the left side of the non-magnetic area, and in the ON state, the object to be held is held by the holding portion due to the magnetic force emitted from the magnetic pole band. [2] A holding device as described in [1], wherein the movable plate includes a magnetic strip consisting of an internal magnetic member spaced apart to the left of the magnetic pole strip, and in the off state, the magnetic pole strip and the magnetic strip connect to the magnetic flux completion portion. [3] A holding device as described in [1] or [2], in which in the holding section, at least one of the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member constitutes one of the holding surfaces, and the object to be held is held on the holding surface. [4] A holding device as described in [3], in which the shape of the holding part when viewed from the front is approximately C-shaped, and the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member, and the surface at the right end where the magnetic members of the holding part are closest to each other in the vertical direction, form the holding surface. [5] A holding device as described in [3], wherein the shape of the holding portion when viewed from the front is an approximately straight shape in which the right side surfaces of the upper right and lower magnetic members are on the same plane, and the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member form the holding surface. [6] A holding device as described in [3], in which the shape of the holding portion when viewed from the front is a generally straight shape with the lower right magnetic member protruding to the right, and the right side surface of the upper right magnetic member and the upper side surface of the protruding portion of the lower right magnetic member form the holding surface. [7] A holding device as described in [3], in which the shape of the holding portion when viewed from the front is a substantially straight shape with the upper right magnetic member protruding to the right, and the right side surface of the lower right magnetic member and the lower side surface of the protruding portion of the upper right magnetic member form the holding surface. [Effects of the Invention]

[0008] The holding device of the present invention can be constructed using only permanent magnets without using electromagnets, thereby achieving both strong holding force and good off-state sharpness without relying on large currents. In particular, providing a magnetic strip on the movable plate dramatically improves off-state sharpness, and simulations have shown that the attractive force in the off-state can be reduced to zero. As specified in claim 1, a movable plate equipped with a permanent magnet is placed between upper and lower plates. When viewed from the front of the device, a non-magnetic area is provided between the holding portion, formed of a magnetic material, and the magnetic flux completion portion. The left-right movement of the movable plate switches between an on-state in which the permanent magnet connects only to the holding portion and an off-state in which it connects only to the magnetic flux completion portion. This configuration allows the device to be made smaller or thinner while maintaining its on-state attractive holding force and good off-state sharpness. For example, it can be constructed as a small holding device with vertical, horizontal, and front-to-back dimensions of approximately 10 cm or less. Alternatively, it can be constructed using thin permanent magnets approximately 2 to 3 mm thick (e.g., a vertical thickness of approximately a few centimeters). If miniaturization is not required, the attractive holding force of the holding portion can be increased by using a large permanent magnet with strong magnetic force. The holding device of the present invention can be used for a variety of purposes, including applications that were difficult to apply with conventional permanent magnet holding devices, and can also be used, for example, as the holding portion of a robot arm for holding an object at least part of which is made of a magnetic material. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic diagram of the structure of the holding device according to the present invention. The holding section is roughly C-shaped, and this is an example of a configuration in which the movable plate has only a magnetic pole band and no magnetic band. The non-magnetic plate body of the movable plate is omitted, and only the magnetic pole band is shown. A is the ON state in which the magnetic pole band is connected to the holding section, and the object to be held is held by the holding section due to the magnetic force emitted from the magnetic pole band. B is an intermediate state between ON and OFF, in which the magnetic pole band is aligned vertically with the upper and lower non-magnetic members. C is the OFF state in which the magnetic pole band is connected to the magnetic flux completion section, and the holding force of the holding section is the weakest. [Figure 2]1 is a diagram showing a schematic diagram of the structure of a holding device according to the present invention. This is an example of a configuration in which the holding section is roughly C-shaped and the movable plate is equipped with a magnetic pole band and a magnetic band. The non-magnetic plate body of the movable plate is omitted, and only the magnetic pole band and magnetic band are shown. A is the ON state in which the magnetic pole band is connected to the holding section, and the object to be held is held by the holding section due to the magnetic force emitted from the magnetic pole band. B is an intermediate state between ON and OFF, in which the magnetic pole band is aligned vertically with the upper and lower non-magnetic members. C is the OFF state in which the magnetic pole band is connected to the magnetic flux completion section, and the holding force of the holding section is the weakest. [Figure 3] Simulation data showing the magnetic flux flow in the XY cross section of the holding device shown in Figure 1, in which the movable plate does not have a magnetic strip, in the on state (A), intermediate state (B), and off state (C). [Figure 4] Simulation data showing the magnetic flux flow in the XY cross section of the holding device shown in Figure 2, in which the movable plate is equipped with a magnetic strip, in the on state (A), intermediate state (B), and off state (C). [Figure 5] 10A and 10B are diagrams illustrating an example of the configuration of the magnetic pole bands on the movable plate as viewed from above. [Figure 6] 10A and 10B are diagrams illustrating an example of the configuration of a magnetic strip when the movable plate has the magnetic strip, as viewed from above. [Figure 7] An example of the configuration of a holding device in which the shape of the holding part is approximately C-shaped (on state). The top diagram shows a schematic diagram from the front (XY cross section), and the bottom diagram shows simulation data. [Figure 8] 10 is a schematic diagram of another example of the configuration of a holding device in which the shape of the holding portion is substantially C-shaped (on state), as viewed from the front (XY cross section). [Figure 9] 10 is yet another example (on state) of the configuration of a holding device in which the shape of the holding portion is substantially C. The upper part shows a schematic diagram as seen from the front (XY cross section), and the lower part shows simulation data. [Figure 10] 10 is yet another example (on state) of the configuration of a holding device in which the shape of the holding portion is substantially C. The upper part shows a schematic diagram as seen from the front (XY cross section), and the lower part shows simulation data. [Figure 11]1 is a schematic diagram of a holding device (on state) in which the holding portion has a substantially straight shape and the right side surface of the magnetic member is flush with one side of the magnetic member without protruding. [Figure 12] An example of the configuration of a holding device (on state) in which the holding part has a substantially straight shape and one side of the magnetic member protrudes to the right. The top diagram shows a schematic diagram from the front (XY cross section), and the bottom diagram shows simulation data. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this specification, when describing the configuration of the holding device, terms such as upper, lower, right side, left side, and front side are used, with the Y direction being the up-down direction, the X direction being the left-right direction, and the Z direction being the front-rear direction, as shown in the three-dimensional axes in Figures 1 and 2. These terms are used for convenience, and do not limit the use state of the holding device of the present invention to use in a state where the Y direction is vertical.

[0011] As used herein, the term "substantially the same" in relation to size (dimensions) means that there may be a difference in size of within 5%, for example, within 3%, or within 1%. The term "same" means that the difference in size is less than 1%, for example, less than 0.5%, or less than 0.1%.

[0012] Although the term "plate" is used in this specification and claims, in the holding device of the present invention, the thickness in the Y direction is greater than the size in the XZ directions, and there may be cases where the shape is more appropriately described as a block rather than a plate. In this specification and claims, the term "plate" is used merely for convenience in order to make it easier to grasp the configuration of the device of the present invention in three dimensions, and the scope of the present invention is not limited to those in which the thickness in the Y direction is sufficiently small compared to the size in the XZ directions.

[0013] The holding device of the present invention uses magnetic force to hold an object, at least a portion of which is made of a magnetic material. As illustrated in FIGS. 1 and 2, the holding device includes an upper plate (20) composed of an upper right magnetic member (210), an upper left magnetic member (220), and an upper non-magnetic member (230) disposed therebetween; a lower plate (30) composed of a lower right magnetic member (310), a lower left magnetic member (320), and a lower non-magnetic member (330) disposed therebetween; and a movable plate (40) composed of at least one permanent magnet with a magnetic pole band (410) arranged on a non-magnetic plate body, the magnetic pole face of which faces vertically. The movable plate (40) is disposed between the upper plate (20) and the lower plate (30) and is movable in the left-right direction. Note that the non-magnetic plate body portion of the movable plate is omitted from the illustration in FIGS. 1 and 2.

[0014] The upper right magnetic member 210 and the lower right magnetic member 310 are spaced apart from each other and do not contact each other, and these magnetic members form the holding portion of the holding device. The upper left magnetic member 220 and the lower left magnetic member 320 are spaced apart from each other and do not contact each other, and these magnetic members form the magnetic flux completion portion of the holding device.

[0015] The upper non-magnetic member (230), which forms part of the upper plate (20), and the lower non-magnetic member (330), which forms part of the lower plate (30), are arranged side by side in the vertical direction, forming a non-magnetic region (70, the region surrounded by a two-dot chain line in Figures 3 and 4) between the holding portion and the magnetic flux completion portion. To the right of the non-magnetic region (70) is the holding portion (50, the region surrounded by a dashed line in Figures 3 and 4), and to the left is the magnetic flux completion portion (60, the region surrounded by a dashed line in Figures 3 and 4).

[0016] The holding device can be switched on (strongest holding force) or off (weakest holding force) by moving the movable plate left and right. In the on state, the object is held by the holding part due to the magnetic force emitted from the magnetic pole band. In the off state, the object can be released or removed from the holding part.

[0017] In the ON state, the magnetic pole strip (410) of the movable plate is connected only to the retaining portion on the right side of the non-magnetic area. Here, "only to the retaining portion" refers to a state in which it is not connected to the magnetic flux completion portion (magnetic members 220, 320) on the left side of the non-magnetic area, but is connected to the retaining portion (magnetic members 210, 310) on the right side. In the ON state, part of the magnetic pole strip (410) may be inside the non-magnetic area, i.e., the permanent magnet constituting the magnetic pole strip may be partially in contact with the non-magnetic member (230, 330) of the non-magnetic area. However, in order to convert the magnetic force of the permanent magnet into a retaining force without loss, it is preferable that the entire magnetic pole strip (410) moves beyond the non-magnetic area to the right, so that the permanent magnet is connected to the magnetic member (210, 310) of the retaining portion without contacting the non-magnetic member (230, 330) of the non-magnetic area, as shown in FIGS. 1A and 2A.

[0018] In the OFF state, the magnetic pole strip (410) of the movable plate is connected only to the magnetic flux completion portion on the left side of the non-magnetic area. Here, "only to the magnetic flux completion portion" refers to a state in which it is not connected to the holding portion (magnetic members 210, 310) on the right side of the non-magnetic area, but is connected to the magnetic flux completion portion (magnetic members 220, 320) on the left side. In the OFF state, a portion of the magnetic pole strip (410) may be within the non-magnetic area, i.e., the permanent magnet constituting the magnetic pole strip may be partially in contact with the non-magnetic member (230, 330) of the non-magnetic area. However, to fully complete the magnetic force of the permanent magnet within the magnetic flux completion portion and minimize the generation of magnetic flux in the holding portion, it is preferable that the entire magnetic pole strip (410) move left beyond the non-magnetic area, so that the permanent magnet is connected to the magnetic member (220, 320) of the magnetic flux completion portion without contacting the non-magnetic member (230, 330) of the non-magnetic area, as shown in FIGS. 1C and 2C.

[0019] The means for operating the left and right movement of the movable plate can be selected appropriately depending on the purpose and environment of the holding device, such as a handle or lever operated by hand, a nut operated with a wrench, or a feed screw, and can also be configured to allow operation from a remote location.Since it only requires a simple left and right sliding movement, it can be operated with just an air compressor.

[0020] 1 and 2, the left-right widths (dimension in the X direction) of the upper non-magnetic member (230) and the lower non-magnetic member (330) are the same, but one of the left-right widths may be smaller than the other. In the holding device of the present invention, it is preferable that the left-right widths of the upper non-magnetic member (230) and the lower non-magnetic member (330) are approximately the same, but this configuration is not limited to this.

[0021] Regarding the front-to-rear dimension (dimension in the Z direction) of the upper non-magnetic member 230, it is preferable that the upper non-magnetic member 230 extend from the front end to the rear end of the upper plate 20, but it is also possible that at least one of the front and rear ends of the upper non-magnetic member 230 does not reach the end of the upper plate 20, and at least one of the front and rear ends of the upper plate has a recess at the position of the upper non-magnetic member 230. Also, in the configuration examples shown in Figures 1 and 2, the front-to-rear dimension of the upper plate and the front-to-rear dimension of the upper non-magnetic member are the same, but it is also possible that the front-to-rear dimension of the upper non-magnetic member is longer, and at least one of the front and rear ends protrudes.

[0022] The same is true for the front-to-rear dimension of the lower non-magnetic member 330. Preferably, the lower non-magnetic member 330 extends from the front end to the rear end of the lower plate 30, but at least one of the front and rear ends of the lower non-magnetic member 330 may not reach the end of the lower plate 30, and at least one of the front and rear ends of the lower plate may have a recess at the position of the lower non-magnetic member 330. The front-to-rear dimension of the lower non-magnetic member may be longer than the front-to-rear dimension of the lower plate, and at least one of the front and rear ends of the non-magnetic member may protrude.

[0023] The magnetic pole band (410) of the movable plate (40) is composed of at least one permanent magnet (411). In the configuration example shown in FIGS. 1 and 2, the lateral width of the magnetic pole band (410) is the same as the lateral width of the upper and lower non-magnetic members (230, 330). However, the lateral width of the magnetic pole band may be larger or smaller. The lateral width of the magnetic pole band is not limited as long as it is possible to achieve a configuration in which the magnetic pole band is connected only to the holding portion and not to the magnetic flux completion portion in the ON state, and the magnetic pole band is connected only to the magnetic flux completion portion and not to the holding portion in the OFF state. In a preferred example of the holding device of the present invention, the lateral width of the magnetic pole band (410) is approximately the same as the lateral width of the upper and lower non-magnetic members (230, 330), but this configuration is not limited thereto.

[0024] The retention device of the present invention includes an embodiment in which the movable plate includes only the magnetic pole strip (410) (FIG. 1), and an embodiment in which the movable plate further includes a magnetic strip (420) (FIG. 2) consisting of an internal magnetic member spaced apart to the left of the magnetic pole strip (410). In the embodiment including the magnetic strip (420), the magnetic pole strip (410) and the magnetic strip (420) connect to the magnetic flux terminating portion in the OFF state (FIG. 2C).

[0025] Figure 3 shows the results of a simulation of magnetic flux in the holding device of the embodiment of Figure 1, in which the movable plate does not include a magnetic strip (420). Figure 4 shows the results of a simulation of magnetic flux in the holding device of the embodiment of Figure 2, in which the movable plate includes a magnetic strip (420). The area surrounded by the dashed line is the holding portion (50) formed by the upper right and lower magnetic members (210, 310), and the area surrounded by the dashed line is the magnetic flux completion portion (60) formed by the upper left and lower magnetic members (220, 320). Comparing the off-state, in the configuration without the magnetic strip, magnetic flux flows in the holding portion (Figure 3C), generating a very small amount of holding force. On the other hand, in the configuration with the magnetic strip, the magnetic flux is completely completed in the magnetic flux completion portion, and no magnetic flux flows in the holding portion (Figure 4C), resulting in zero holding force in the simulation. Device configurations including magnetic strips are particularly preferable for use in situations where low adhesive holding force in the off-state is important, such as in the gripping portion of a robot arm.

[0026] The magnetic pole band of the movable plate may be composed of one permanent magnet or two or more permanent magnets. The permanent magnets are arranged on the movable plate with their pole faces facing up and down. Either the south pole or the north pole may face upward. When composed of two or more permanent magnets, it is sufficient that the pole faces of 80% or more of the permanent magnets, for example, 90% or more of the permanent magnets, face in the same direction, but it is more preferable that the pole faces of all the permanent magnets face in the same direction (for example, all the permanent magnets face in the same direction, either the south pole or the north pole).

[0027] FIG. 5 shows some configuration examples of the magnetic pole band in the holding device of the present invention. When a single permanent magnet is used, a permanent magnet (411) having the same length as the front-to-rear dimension of the movable plate (40) may be used, as shown in FIG. 5A. Alternatively, a permanent magnet (411) having a shorter length than the front-to-rear dimension of the movable plate (40) may be used, as shown in FIG. 5B. When two or more permanent magnets are used, multiple permanent magnets (411) may be arranged in the left-to-right direction, as shown in FIG. 5C, or in the front-to-rear direction, as shown in FIG. 5D. When multiple permanent magnets are arranged in the left-to-right direction to form the magnetic pole band, the left-to-right width of the magnetic pole band is the dimension from the left end of the leftmost permanent magnet to the right end of the rightmost permanent magnet. Furthermore, when multiple permanent magnets are arranged in the front-to-rear direction to form the magnetic pole band, the front-to-rear dimension of the magnetic pole band is the dimension from the rear end of the rearmost permanent magnet to the front end of the foremost permanent magnet.

[0028] When the movable plate includes a magnetic strip (420), the magnetic strip may be composed of one internal magnetic member or two or more internal magnetic members. Some configuration examples of the magnetic strip in the holding device of the present invention are shown in FIG. 6. In FIG. 6, the magnetic pole strip (410) adopts the configuration of FIG. 5A for convenience, but is not limited to this, and other configurations such as those shown in FIGS. 5B to 5D may also be adopted. When composed of one internal magnetic member, an internal magnetic member (421) having the same length as the front-to-rear dimension of the movable plate (40) may be used as shown in FIG. 6A, or an internal magnetic member (421) having a length shorter than the front-to-rear dimension of the movable plate (40) may be used as shown in FIG. 5B. When composed of two or more internal magnetic members, multiple internal magnetic members (421) may be arranged in the left-to-right direction as shown in FIG. 5C, or in the front-to-rear direction as shown in FIG. 5D.

[0029] The width of the magnetic strip 420 may be the same as the width of the magnetic pole strip 410, as in the illustrated example, or one width may be smaller than the other. In a typical example of a holding device in which the movable plate has the magnetic strip 420, the width of the magnetic strip 420 is approximately the same as the width of the magnetic pole strip 410, but this configuration is not limited thereto.

[0030] In the illustrated configuration example, the distance between the magnetic pole band and the magnetic band is the same as the left-right width of the upper and lower non-magnetic members (230, 330), but the distance between the magnetic pole band and the magnetic band may be larger or smaller than the left-right width of the upper and lower non-magnetic members (230, 330). In one example of the holding device of the present invention, the distance between the magnetic pole band and the magnetic band is approximately the same as the left-right width of the upper and lower non-magnetic members (230, 330), but is not limited to this configuration.

[0031] In the holding device of the present invention, the position of the holding surface when the holding part holds the object to be held can vary depending on the shape of the holding part, but the fact that at least one of the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member constitutes one of the holding surfaces is common to various shapes. Specific examples of the shape of the holding part in the holding device of the present invention and the position of the holding surface in each example will be described below with reference to Figures 7 to 12. Figures 7 to 12 are schematic diagrams of the holding device (XY cross section) when viewed from the front.

[0032] FIG. 7 shows an example of a holding device configuration in which the holding portion (50) is approximately C-shaped in front view. The approximately C-shape is the simplest configuration, with the upper and lower magnetic members (210, 310) extending straight in the left-right direction, with the upper right magnetic member (210) protruding downward at the right end and the lower right magnetic member (310) protruding upward. Simulation data for magnetic flux in this configuration is shown in the lower part of FIG. 7, with the four surfaces indicated by thick lines forming holding surfaces. In a holding device with an approximately C-shaped holding portion, the right side surface (52a) of the upper right magnetic member (210), the right side surface (52a') of the lower right magnetic member (310), and the surfaces (52b, 52b') of the magnetic members of the holding portion at the right end that are closest to each other in the vertical direction form holding surfaces.

[0033] 8 shows an example of a roughly C-shaped configuration in which one magnetic member protrudes toward the other at the right end of the holder. In this case, too, the areas indicated by the thick lines in the figure, i.e., the right side surface (52a) of the upper right magnetic member (210), the right side surface (52a') of the lower right magnetic member (310), and the surfaces (52b, 52b') of the magnetic members of the holder at the right end that are closest to each other in the vertical direction, form the holding surfaces.

[0034] FIG. 9 shows another example of a holding device configuration in which the holding portion (50) has a generally C-shaped configuration in front view. At the right end of the holding portion, the upper and lower magnetic members protrude upward and downward, respectively, and extend to the right, after which the upper right magnetic member (210) protrudes downward and the lower right magnetic member (310) protrudes upward, forming a generally C-shaped configuration. Simulation data for magnetic flux in this configuration is shown in the lower part of FIG. 9, and the four surfaces indicated by the thick lines form holding surfaces. That is, even in this generally C-shaped configuration, which is more complex than those shown in FIGS. 7 and 8, the right side surface (52a) of the upper right magnetic member (210), the right side surface (52a') of the lower right magnetic member (310), and the surfaces (52b, 52b') of the magnetic members of the holding portion at the right end that are closest to each other in the vertical direction form holding surfaces.

[0035] FIG. 10 shows another example of a holding device configuration in which the holding portion (50) has a generally C-shaped configuration in front view. Only the lower right magnetic member (310) protrudes downward midway and extends to the right, while the upper right magnetic member (210) has a shape similar to that of the upper right magnetic member shown in FIG. 7, resulting in a somewhat complex, generally C-shaped configuration. Simulation data for the magnetic flux in this configuration is shown in the lower part of FIG. 10, and the four surfaces indicated by the bold lines form holding surfaces. That is, even in this generally C-shaped configuration, the right side surface (52a) of the upper right magnetic member (210), the right side surface (52a') of the lower right magnetic member (310), and the surfaces (52b, 52b') of the right end of the magnetic member of the holding portion that are closest to each other in the vertical direction form holding surfaces.

[0036] 11 shows an example of a holding device having a holding portion (50) with a substantially straight shape in front view, in which the right side surfaces of the upper right and lower magnetic members are flush with each other (i.e., the right end does not protrude). In this configuration, the right side surface (52a) of the upper right magnetic member (210) and the right side surface (52a') of the lower right magnetic member (310) form a holding surface.

[0037] Figure 12 shows an example of a configuration of a holding device in which the holding portion (50) has a generally straight shape in a front view, in which one of the magnetic members protrudes to the right, such as a protruding lower right magnetic member (310). In the configuration of Figure 12, the right side surface (52a) of the upper right magnetic member (210), which is the non-protruding magnetic member, and the upper side surface (52b') of the protruding portion of the lower right magnetic member, which is the protruding magnetic member, form the holding surface. Conversely to Figure 12, in a configuration in which the upper right magnetic member (210) protrudes more, the right side surface of the lower right magnetic member (310), which is the non-protruding magnetic member, and the lower side surface of the protruding portion of the upper right magnetic member, which is the protruding magnetic member, form the holding surface.

[0038] The magnetic members (210, 310, 220, 320) constituting the retaining portion and the magnetic flux completing portion, and the internal magnetic member (421) constituting the magnetic strip that the movable plate may have, are made of magnetic material. Specific examples of magnetic materials include iron, cobalt, nickel, and gadolinium, as well as compounds containing one or more of iron, cobalt, nickel, gadolinium, chromium, and manganese, and materials such as martensitic stainless steel. All of the above-mentioned parts may be made of the same magnetic material, or some or all of the parts may be made of different magnetic materials.

[0039] The non-magnetic members (230, 330) that make up the non-magnetic area and the main body of the movable plate are made of non-magnetic materials. "Non-magnetic material" does not mean a material that is completely impermeable to magnetic force; rather, it refers to a material that has a significantly higher magnetic permeability (e.g., several hundred to several thousand times higher) than the magnetic material being used. Specific examples of non-magnetic materials include non-magnetic metals such as copper, zinc, tin, lead, aluminum, magnesium, sulfur, and titanium, or compounds containing one or more of these elements (e.g., brass, bronze, etc.), austenitic stainless steel, and other non-magnetic metals; petroleum-based materials such as plastic, polyethylene, and vinyl; non-metallic and non-petroleum-based materials such as rubber and glass; and plant-derived materials such as natural fibers (e.g., cotton), natural resins, wood, and wood-based products (e.g., paper).

[0040] The holding device of the present invention can be constructed using only permanent magnets without using electromagnets, thereby achieving both sufficient holding force and sharp cutoff without relying on large currents. In particular, by incorporating a magnetic strip into the movable plate, simulations have shown that the attractive holding force during the off state can be reduced to zero. While the holding device of the present invention can increase the attractive holding force of the holding unit by using large, strong permanent magnets, it is suitable for holding relatively lightweight objects and can be made smaller and thinner than conventional permanent magnet-based holding devices. The holding device of the present invention can be used in a variety of applications, including those that were difficult to apply with conventional permanent magnet-based holding devices. Since the left-right movement of the movable plate can be controlled using only an air compressor, as described above, the holding device of the present invention can also be used in the gripping unit of a robot arm for gripping objects at least partially made of magnetic material. [Explanation of symbols]

[0041] 10 Holding device 20 Upper Plate 210 Upper right magnetic member 220 Upper left magnetic member 230 Upper non-magnetic member 30 Lower Plate 310 Lower right magnetic member 320 Lower left magnetic member 330 Lower non-magnetic member 40 Movable Plate 410 Magnetic pole 411 Permanent Magnets 420 Magnetic Strip 421 Internal magnetic components 50 Holding part 52a, 52b, 52a', 52b' holding surface 60 Magnetic flux completion part 70 Non-magnetic area

Claims

1. A holding device that holds an object, at least a portion of which is made of a magnetic material, by magnetic force, an upper plate including an upper right magnetic member, an upper left magnetic member, and an upper non-magnetic member disposed therebetween; a lower plate including a right lower magnetic member, a left lower magnetic member, and a lower non-magnetic member disposed therebetween; a movable plate in which a magnetic pole band, which is made of at least one permanent magnet and has a magnetic pole surface facing up and down, is arranged on a non-magnetic plate body; Equipped with the movable plate is disposed between the upper plate and the lower plate and is movable in the left-right direction; the upper right magnetic member and the lower right magnetic member are spaced apart and do not contact each other, and these magnetic members form the holding portion of the holding device; the upper left magnetic member and the lower left magnetic member are spaced apart and do not contact each other, and these magnetic members form a magnetic flux completion portion of the holding device; the upper non-magnetic member and the lower non-magnetic member are arranged side by side in the vertical direction to form a non-magnetic region between the holding portion and the magnetic flux completing portion; A holding device in which the movable plate can be moved left and right to switch between an ON state in which the magnetic pole band is connected only to the holding portion on the right side of the non-magnetic area, and an OFF state in which the magnetic pole band is connected only to the magnetic flux completion portion on the left side of the non-magnetic area, and in the ON state, the object to be held is held by the holding portion due to the magnetic force emitted from the magnetic pole band.

2. 2. The retaining device of claim 1, wherein the movable plate includes a magnetic strip comprised of an internal magnetic member spaced to the left of the magnetic pole strip, and in the off state, the magnetic pole strip and the magnetic strip connect to the magnetic flux completion portion.

3. 3. The holding device according to claim 1, wherein in the holding portion, at least one of the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member constitutes one of the holding surfaces, and the object to be held is held on the holding surface.

4. A holding device as described in claim 3, wherein the shape of the holding portion when viewed from the front is approximately C-shaped, and the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member, and the surface at the right end where the magnetic members of the holding portion are closest to each other in the vertical direction, form the holding surface.

5. A holding device as described in claim 3, wherein the shape of the holding portion when viewed from the front is an approximately straight shape in which the right side surfaces of the upper right and lower magnetic members are on the same plane, and the right side surface of the upper right magnetic member and the right side surface of the lower right magnetic member form the holding surface.

6. A holding device as described in claim 3, wherein the shape of the holding portion when viewed from the front is an approximately straight shape with the lower right magnetic member protruding to the right, and the right side surface of the upper right magnetic member and the upper side surface of the protruding portion of the lower right magnetic member form the holding surface.

7. A holding device as described in claim 3, wherein the shape of the holding portion when viewed from the front is an approximately straight shape with the upper right magnetic member protruding to the right, and the right side surface of the lower right magnetic member and the lower side surface of the protruding portion of the upper right magnetic member form the holding surface.

Images